Method and apparatus for drying tobacco products



March 13, 1956 R|EGGER 2,737,955

METHOD AND APPARATUS FOR DRYING TOBACCO PRODUCTS Filed Feb. 8, 1950 FIG. I 1 2b E m Q3: K

T F 40 I FIG. 2

E] [El 5 6b 24 a for the drying process in a novel manner.

United States METHOD AND APPARATUS FOR DRYING TOBACCO PRODUCTS Application February 8, 1950, Serial No. 143,091

7 Claims. Cl. 131-25 This invention relates generally to a method and apparatus for drying tobacco products and more particularly to a drying process by dielectric heating. 1

To give tobacco products, especially cigarettes and cigars, the final touch preparatory to shipment and smoking, they have to be subjected to a final drying treatment. A number of methods to eifect this drying operation have been devised and are well known in the art of tobacco product manufacturing. All of these methods, however, have the disadvantage that they do not allow to dry the tobacco products in such a short time that drying could be performed within a continuous operating cycleof producing and packing machines. It is, for example, customary, to deposit cigarettes, issuing from a cigarette making machine, in racks or frames which subsequently aremoved about and so hinder the continuous fiow of goods. Although the working rooms may be air-conditioned, it is nevertheless impossible to prevent that the tobacco products, on their way from machine to package, thus get affected in their taste and flavor by external influence.

The present invention has as its object, to preventthe disadvantage just enumerated and to provide a drying method for tobacco products, which may exceptionally well be incorporated into a coordinated operating cycle of producing and packing machines, and thereby make a drying process adaptable to a continuous production line. To reach this end, this invention applies a dielectric field Dielectric heating within a dielectric field of a frequency of above 3 megacycles has already been used for drying tobacco or the like, but previous to this invention, the fact has not been recognized that by correct distribution and intensity of the dielectric field, and by a suitable arrangement of producing and packing machines, a continuous production, including a dielectric drying treatment, may be obtained.

According to the present invention, the rate of movement of the products through a dielectric field is timed in such a manner to the rate of speed and capacity of the invloved producing and packing machines that all coacting machines work in perfect coordination with each other, with conveying means, and with the dielectric heating device, so a continuous process is assured and a properly dried product issues.

Other features and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawing, in which- Fig. 1 shows diagrammatically a plan side elevation of an embodiment of the invention as used for drying of cigarettes;

Fig. 2 is a diagrammatic top view of the same apparatus; I

as in Fig. 1;

Fig. 3 is a sectional view of a set of heating electrodes as applied for dielectric drying of cigarettes right in the cigarette making machine on the lay-ofi drum.

Referring now to the drawing, a cigarette making machine is shown at 1, an endless conveying belt 4 passes with its upper strand between dielectric heating electrodes 2a, 215, whereas a cigarette packing machine is shown at 3. In operation, the cigarettes issuing from machine 1, drop not, as has up to now been customary, on a rack, but on one end 4a of the conveying belt 4, whose upper strand passes through a dielectric field created between electrodes Zn on the lower side, and 2b on the upper side ofsaid upper strand. As the'high frequency source, supplying power to the electrodes, is no part of this invention it is not shown on the drawing, but any suitable electronic generator or oscillator may be used. The cigarettes, put on the upper strand of the moving belt 4 by machine 1, pass thedielectric field on their way to packing machine 3 and are thereby dried by dielectric heating. Dropping oif on the other'end 4b of the conveying belt 4, the cigarettes enter directly into "the hopper of the packing machine 3 to be readily packed for subsequent storage and shipment. i To bring about eiiicient operation of the equipment, care has to be taken and means to be provided that the machines 1 and 3, as well as conveying belt 4, cooperate to assure a continuous flow of goods. For this purpose changes of shape, size, and location of parts can be made, and several adjusting and control means are provided. Besides using differing sizes and shapes of electrodes 2a, 2b,'and besides adjusting means for the intensity of the dielectric field along the conveying belt 4, and adjusting means for the rate of its speed, provisions are made for applying dielectric fields at several points on the run of the cigarettes, to speed up the drying process if conditions require. Furthermore, fields of differing intensities may be applied at the several points. It is, for example, possible to apply additional dielectric drying to the cigarettes, while the same lie on the rotating lay-ofi drum 5 of the cigarette making machine 1, whereby the electrodes 6a, 6b may be disposed at both end surfaces of said drum, as illustrated on the drawing. In this case, drying of the cigarettes takes place in the cigarette making machine itself which may sufiice under certain conditions. The pre-dried cigarettes, dropping from lay-oil drum 5 onto conveyor 4, take the same way toward packing machine 3 as cigarettes not dried in this manner.

The shape and size of the dielectric heating electrodes 2a, 211 or 6a, 6b may vary widely and they may readily be adapted to suit space and conditions. They may be fiat, arcuate, or cylindrical. An especially intricate shaped set of electrodes, as used in an embodiment of this invention, is shown, by way of example, in Fig. 3. An arcuate-shaped electrode 7a faced with a heat dissipating and insulating lining 8 preferably of material known under the trademark Trolitur, is disposed concentrically around a portion of the cylindrical surface of the lay-01f drum 5, onto which just made cigarettes issue from the machine. Trolitur is a pure hydrocarbon of the group of polystyroles which belongs to the high polymer vinyl combinations. This substance is as clear as glass and possesses extreme dielectric properties and is stable against alkalis, acids, alcohol and water but is unstable against either benzol, benzine, ketones and turpentine. The hub of the rotatable lay-off drum serves thereby as counter-electrode 7b and high frequency power is charged into said hub by a slip-contact 9. As the body of the lay-off drum 5, is preferably made out of plastic, the cigarettes passing the electrodes face insulating material on both sides. It has namely been found that metal concentrates the dielectric heat so much to become harmful to the cigarettes.

It will be understood that various modifications, difierent construction and arrangement of parts, and other alterations of the just described embodiments of this invention are possible, and I do not wish to be limited to the illustrated examples, butdesire the appended claims to be construed as broadly as possible in view ofttheprior art.

What I claim is:

1. In an installation for manufacturing vandnpacking tobacco products, a production machine, a packing machine, means for continuously conveying. the products from said production machine to said packing machine, lay-off means in saidproduction machine for transferring the products tosaid conveying means, and means for producing and maintaining a high frequencytdielectric field on a part of said layvotf means and said conveying means.

2. In an installation formanufacturing .and packing tobacco products, a production machine, a packing .machine, conveyor means .fortra'nsferringsaid products from the production machine to the. packing machine,

lay-0P1 means insaid production machine for transferring the products to said conveyor, high frequency dielectric field producing means surrounding part of said lay-off means and conveyor means, andmeanslfor synchronizing the operation of said production machine, lay-off means, conveyor means, and packing machine.

3. An installation as set forth in claim 2, in which said high frequency dielectric field producing means include a pair of cooperating electrodes disposed one at eachside of said lay off means. 4. An installation as set forth in claim 2, in which said lay-off means is a drum having a hub rotatably mounted on a shaft, said high frequency dielectric means includ ing an arcuate electrode concentrically surrounding part of said drum, and said. hubforming a secondelectrod cooperating with said arcuateelectrode.

5. In an installation for manufacturing and packing tobacco products, a production machine, a packing machine, an endless conveyor for transferring said products from the production machine to the packing machine, a rotatably mounted lay-01f drum in said productionmachine for transferring said products to the conveyor,

means for synchronizing the movements of said drum,

' conveyor, and packing machine, and high frequency dielectric field producing electrodes surrounding part of said drum and conveyor.

6. In an installation for manufacturing and packing cigarettes, a cigarette fabricating machine, a rotatably mounted lay-off drum in said fabricating machine, a packing machine, an endless conveyor for transferring the cigarettes from said lay-off drum to said packing machine, and a plurality of high frequency dielectric field producingv electrodes disposed adjacent said layfoif drum and conveyor so as to produce high frequencydielectric fields on the surfaces thereof, the operation of said fabfloating-machine, lay-off drum, conveyor, packing machine and electrodes being synchronized to ensure continuous assembly line type production.

7. An installation as set forth in claim 6, including a pair of. electrodes one at each end of said lay-ofi-drum an 1 :both curved substantially as the periphery of the drum.

. References Cited in the file of this patent .UNITED STATES PATENTS 1,224,703 Benjamin May 1, 1917 1,555,258 Allcutt Sept. 29, 1925 1,757,477 Rosenhoch May 6, 1930 1,783,093 Molins Nov. 25, 1930 "1,900,573 "-McArthur Mar. 7, 1933 1,982,292 Granstedt Nov. 27, 1934 2,000,684 Allen et al. May 7,1935 2,010,486 Herrmann Aug. 6, 1935 2,109,617 Gwinn et al. Mar. 1, 1938 2,330,000 Molins Sept. 21, 1943 2,415,025 -Grell et al. Jan.'28, 1947 "2,479,351 'Hogopian Aug. 16, 1949 FOREIGN PATENTS 331,026 Great Britain June 26,- 1930 I 407,757 Italy Nov. 20, 1944 599,899 Great Britain Mar. 23,- 1948 

